title: SPDL-1 functions as a kinetochore receptor for MDF-1 in Caenorhabditis elegans.
abstract: The spindle assembly checkpoint (SAC) ensures faithful chromosome segregation by delaying anaphase onset until all sister kinetochores are attached to bipolar spindles. An RNA interference screen for synthetic genetic interactors with a conserved SAC gene, san-1/MAD3, identified spdl-1, a Caenorhabditis elegans homologue of Spindly. SPDL-1 protein localizes to the kinetochore from prometaphase to metaphase, and this depends on KNL-1, a highly conserved kinetochore protein, and CZW-1/ZW10, a component of the ROD-ZW10-ZWILCH complex. In two-cell-stage embryos harboring abnormal monopolar spindles, SPDL-1 is required to induce the SAC-dependent mitotic delay and localizes the SAC protein MDF-1/MAD1 to the kinetochore facing away from the spindle pole. In addition, SPDL-1 coimmunoprecipitates with MDF-1/MAD1 in vivo. These results suggest that SPDL-1 functions in a kinetochore receptor of MDF-1/MAD1 to induce SAC function.
authors.affiliation: Department of Molecular Pharmacology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: Takaharu G
authors.initials: TG
authors.lastname: Yamamoto
authors.forename: Sonoko
authors.initials: S
authors.lastname: Watanabe
authors.forename: Anthony
authors.initials: A
authors.lastname: Essex
authors.forename: Risa
authors.initials: R
authors.lastname: Kitagawa
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D016764:Cell Polarity; D018385:Centrosome / Q000378:metabolism; D020090:Chromosome Segregation; D020964:Embryo Loss; D004625:Embryo, Nonmammalian / Q000166:cytology; D017238:Genes, Helminth; D018386:Kinetochores / Q000378:metabolism*; D008540:Meiosis; D011485:Protein Binding; D021381:Protein Transport; D034622:RNA Interference; D008941:Spindle Apparatus / Q000378:metabolism; D013489:Suppression, Genetic
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; C412839:MDF-1 protein, C elegans; C532870:SPDL-1 protein, C elegans